A light dimmer is used to adjust power that is supplied to a lamp in order to adjust the brightness (amount of light) emitted by the lamp. An incandescent lamp's illumination is based on thermal radiation. Therefore, both output brightness and correlated color temperature (CCT) of an incandescent lamp's emitted light is a positive function of the lamp's input power, in that both brightness and CCT increase with increasing input power and decrease with decreasing power.